Do you ever have the thought that everything we think we know about something is wrong? It happens to me all the time. It can be disconcerting, but it can also be pretty exhilarating. I couldn’t sleep the other night and I started to think about time. To be more specific, time travel. (Legends of Tomorrow is a time travel show and is fantastic. That’s what sparked it.) But it came back to time in general. It struck me that I really have no idea what time is. I can read a clock, figure out acceleration, speed, tempos in music, and stuff like that, but I still don’t know what time is. What’s it made of? How does it work? When physicists say that time slows down at high velocities, what does that even mean?
Sometimes people talk about time as a fourth dimension. That doesn’t help very much. We have length, width, height, and time? It doesn’t seem to be the same sort of thing as the other three. People also say that when we look at distant stars, we are looking back in time. Are we, though? Aren’t we seeing the light as it is right now? If we are looking into the past, why only for distant stars? Aren’t we looking into the past every time we look at anything? It might only be fractions of a millisecond into the past, but shouldn’t we be consistent? When we hear a distant sound, are we listening to the past? Are we ever experiencing the present?
Why do we think we’d bump into ourselves if we traveled back in time? We don’t bump into ourselves when we travel back in space. If it’s really spacetime instead of space and time, shouldn’t they work the same way? Is the time in physics equations even the same thing that we’re talking about when speculating about time travel and things like that? How do we experience time anyway? It doesn’t seem like we can see it, touch it, smell it, hear it, or taste it. It seems as slippery as Hume’s self.
I could go on, but I think you get the point. I know nothing about time. Or maybe it’s more precise to say I’m uncertain about everything when it comes to time. I’d love to know. Please explain it to me if you can.